Perforating gun and projectile therefor



Sept. 30, 1941. w. s. REYNOLDS 2,257,275

' l I PERFORATING GUN AND PROJECTILE THEREFOR Filed March 14, 1938 66 MMO@ @fmee ATTORNEY IPatentecl Sept. 30, 1941 Waldo Se. Reynolds, Los Angeles, Calif., assignor to Ira J. McCullough, Los Angeles-Calif.

Application -March 14, 1938, Serial No. 195,759

4 Claims.

My invention relates, in general, to the perforating of well casing, and relates in particular to a device whereby such casing is perforated by projectiles which are driven therethrough at high velocity.

It is an object of the'invention to provide'a perforating device of the above character including a gun b ody including a gun barrel with a chamber for a Aiiring charge of explosive material at the inner end of the gun barrel, with a'projectile disposed at the inner end of such gun-barrel, these parts being of simple `form and cooperating in such manner that maximum velocity oi the proi jectile vfor' a given firing charge is, at all times,

assured.

It is a further object of the invention to provide, in a perforating device of the above char-l acter, parts which are so formed in cooperating relation that maximum length of gun barrel may be'maintained, and a longer projectile travel secured than has been heretofore possible in well casing perforating guns for a gun barrel of given diameter and length. For a given ririg charge two of the factors which determine the penetrating capacity of the projectile are the muzzle velocity of'the projectile and the mass of such projectile as compared to its diameter. Accord--V ingly, by increasing the length of travel of the projectile in the gun barrel Without increasing the length of the gun barrel, and without iricreasing the mass of the projectile. I havev been able to materially increase the penetrating capacity of the projectile.'

An additional factor entering into the penetrating capacity of a projectile propelled by a given iiring charge is the control of movement of the projectile from its initial position until a high pressure is built up in the firing-'charge chamber so that when the projectile is released it will be propelled forwardly by this high pressure produced by' the burning of the firing charge. It is k an object of 'the present invention to provide, in a gun perforating device for well casing, aprojectile having ,a collar projecting. radially from its'inner end portion, and cooperating parts in the structure of the gun for gripping this collar when the projectile is in position within the gun, such collai` providing a means for holding the projectile from outward movementl \until a desired high pressure has been built up .in the' firingcharge chamber, whereupon the collaris sheared and the projectile released and propelled at high velocity' by the firing charge.- e

`It is a further object of the; invention to prowill cooperate with a projectile having a collar at the inner end thereof in 'such manner that theI outer end of the ming-charge chamber will be positively sealed against entrance of moisture..

so that outward movement of the projectile cannot occur until the desired high pressure has been built up in the 'iiring-charge chamber, and

so that the projectile cannot be moved into the I ring-ch'arge chamber by well pressure applied to the outer end of a projectile when the perorating device is submerged in the :fluid contents of a well. s

It is a further object ofthe invention to provide .a novel well casing perforating projectile having a collar at its inner end and also a novel method of forming a collared projectile 'of the character hereinbefore described. y

It is a. still further object of my invention to provide a method whereby a projectile may be provided with an outwardly extending sealing collar. v

It is a still further object of my invention to provide such a methodin which a tight seal is formed between the sealing collar and theprojectile and in which the two are secured together so that the projectile will be released when a predetermined explosive pressure is applied thereto. One of the important advantages of my invention vis that vit is possible to produce large numbers of projectiles and collars in which the explosive pressure' required to release the projectile from the' collar`is substantially uniform. v

of the projectiles be released at substantially the the specicatiom vide, infawell casing perforating gun, parts which 55 invention.

same time.

It is a further object of the invention to provide a. well .casing periorating projectile having a collar at its inner end which cooperates with 4'0 the gun structure in the manner previously described, and which shears, when the gun is .red, in a manner to leave a ring on the projectile which makes sealing engagement with the bore of l the perforator barrel and' prevents escape of propelling gases past the projectile duringy its travel through thegun barrel. Y

Further objects and advantages of the invention will be broughtout in the following part of Referring tothe drawing which is for illustrative purposes only: s

Fig. 1 is a partly sectioned view oi a well casing perforating device embodying my present Awhich receives a shank Fig. '7 is an enlarged fragmentary sectional x view showing my preferred form of engagement between the projectile body and the collar.

In Fig; l I show a well casing perforating device III comprising a gun II adapted to be lowered within a well casing by means of a cable I2 and carrying projectiles I3 adapted to be propelled outwardlyvat high velocity throughthe wall of the well casing by the explosive action of charges of powder. The gun II includes a body I4 having a threaded opening I5 at its upper end, into which an extension I6 is screwed, this extension having a threaded opening I1 at its upper end I8 provided with a threaded pin I9 to which a cable socket 26 is secured so as to connect the cable I2 to the gun II.

In the upper part of the gun body I4 there is an opening 2I serving as a receptacle for a block `22 having a vertical opening 23 in the upper end of which a priming device in the form of a percussion cap 24 is received. One side of the opening 2I communicates with a threaded opening 25 through which the block 22 may be moved in and out of the opening 2I, and having therein a threaded plug 26 for holding and sealing the block 22 in place. A replaceable ring pin 21 is disposed above the priming device 24, this ring pin extending within an opening in the upper part of the body I4, and through an opening 28 in the lower part of the extension I6, the ring pin 21 having a head 30 positioned in a lateral opening 3| in the lower part of the extension I6 and being connected by means of an internally threaded cup member to the threaded lower end 33 of a bar 34. The bar 34 has a head 35 on the lower end which may be moved downwardly through an axial opening 36 in the extension I6 to the position in which it is shown, and the upper end of the bar 34 projects through anopening 31 in Ithe lower threaded end 38 of the shank I8, into a lateral opening 39 in such shank. The upper end of the bar 34 is provided with a transverse shear pin 40 which supports the bar 34 and the ring pin 21 in` raised position, as shown. A- percussion sleeve 4I surrounds the upper portion of the shank I8, and has screws 42 for frictional engagement with side walls 43 of the shank I8. Just prior to the lowering of the perforating device I0 into a well, a cross-bar 44, is placed in the opening 39 of the shank I6 in such position that it will engage the upper extremity of the bar 34 when the ends of the crossbar 44 are in position to be engaged by the lower end face of the percussion `sleeve 4I.

The opening 23 in the block 22 is connected through a vertical opening 45 with an ignitioncharge chamber 46, the outer end of which is closed and sealed by a plug 41 and the inner end of which communicates through a port 48 with an ignition passage 49 which extends down through one side of the body I4 to the lower end thereof, the lower end of the ign-itionfpassage 49 being closed by a screw 50. Extended inwardly in alternated relation from opposite sides of the body I4 are threaded openings 5I, such openings being counterbored as clearly shown at 52 in Fig.

2. The intermediate section 53 of the body I4 isA shown rotated through an angle of so that the alternate relation of the openings 5I may be clearly shown. At the inner end of each opening 5I there is a firing-charge chamber 54 which is connected to `the ignition passage 49 by means of an ignition port 55. The relative diameter of the openings 5I and the firing-charge chamber 54 are such that an outwardly faced shoulder 56 is formed between the outer end of the chamber 54 and the inner end of the opening 5I.

A cylindrical member 56 is removably secured in each opening 5I, preferably by use of threaded engagement between the exterior of the member 56 and the wall of the opening 5 I The cylindrical member 56 provides a gun barrel having a bore 51, the inner end 5B of'which bore is slightly ared, as shown. A projectile I3 is disposed at the inner end of each bore 51 so that when a firing charge 58 in the cooperating firing-charge chamber 54 is ignited, the projectile I3 will be propelled through the entire length of the bore 51. The projectile I3 is provided with a radially projecting collar 59, which collar 59 is in the form of a radially projecting flange and is fixed at or near the inner end of the projectile I3 so that at least the outer portion thereof will lie between the shoulder 56 and the inner end 60 of the removable member 56, to be tightly gripped or clamped therebetween when the member 56 is screwed in tightly by the application of a suitable wrench to the outer end 6I thereof.

The collar 59 is preferably made of such material that an annular center portion thereof will shear from that portion thereof which lies adjacent the end 6U of the cylindrical member 56, when a high pressure is built up in the firingcharge chamber 54. The center portion of the collar 59 which remains with the body of the bullet I3 forms a ring which has an external diameter slightly larger than the body of the projectile and serves as a sealing Vring around the same as the projectile passes outwardly through the bore 51. The collar 59, by selective use of the factors of thickness and shearing characteristics, is enabled to maintain a desired control of the release of the projectile at a desired pressure produced in the chamber 54 by the ignition of a firing charge 58 therein. To positively seal the outer end of the firing-charge chamber 54, the inner end of the projectile I3 andthe collar 59 are provided with a coating of gasket forming material 10, one type of which will be more fully described hereinafter.

The preferred form of my casing perforating projectile I3, as shown to enlarged scale in Fig. 3, is made in the following manner. As sh/own in Fig. 4, a cylindrical projectile body 63 is prepared for penetration, as by formation of a f conical point 64 thereof. It will be understood however that this conical point 64 is not necessary in all practices of the invention, but the projectile body 63 may be prepared for. penetration by `other point forms. Near the inner' end 65 of the body 63 an annular groove 66 is formed. A collar ring' 61 is formed, which ring is dished so that the opening 68 therethrough will receive the projectile body 63. Then, as shown in Fig.' 5, the collar-ring 61 is moved onto the projectile body 63 to such position that the inner edge portion 69 thereof will coincide with the groove 66.

shown in Fig. 6, the collar ring 61 is then fiattened so that the inner edge portion 69 thereof.

will `enter the groove 66 of the projectile body 63, thereby fixing the ring 61 on the projectile body 63 so as to form a radially projecting collar 59, such as s hown in Figs. 2 and 3. 'Ihe projectile bodywith its affixed collar is then held with the point 64 facing upwardly and the lower portion of lthe projectile structure is dipped in a soldering compound, for 'example soldering acid, after which the inner'half of the projectile I3 is im- "mersed in a bath of hot metal of solder-like chare acteristics, for example, lead, zinc or tin, or other suitable deformable gasket-forming alloy, thereby applying to the inner end of the projectile I3 a layer of deformable gasket-forming material which covers the rinner end 65 of the body 63, the inner 4face 1I, the peripheral face 12, and the outer face 13 of the collar 59, and also that porton- 14` of the projectile body 63 lying adjacent the outer face 13 of the collar 59. The portion 15 of the gasket coating 10 which surrounds and adheres to the portion 14 of the projectile body 63 is tapered, and when the projectile I 3 is placed in the inner end of the bore 51, such portion 15 will extend into the flared enlargement 58 of the inner end of the bore 51.

' Owing to the fact that the gasket layer 10 adheres to, or is fused onto, the projectile structure, the joint 16 between the collar59 and the groove 6.6 will be perfectly sealed. Likewise, when'the tapered portion 15 of the gasket layer 16 is forcedl into the flared enlargement 58 at the inner end of the bore 51, the 'tapered portion 15 will be coinpressed tightly into the aimular corner formed by the 'outer face 13 of the collar 59 and the cylindrical face of the projectile body' 63.

The inner end'65 of the projectile I3, as shown in Fig. 2, projects a short distance into ther firingcharge chamber 54, which is accomplished preferably by setting the entire projectile inwardly. This is made possible, 'to any extent desired, by the distance of the collar 59 from the inner end of the projectile. When the cylindrical member 56 is screwed tightly into place so as to deform the gasket layer 10 into sealing conformity to or engagement with the shoulder 56 of the end 60 ,of the member 56, the inner end 65 of the projectile 13 may be employed to compress the firing charge 58.v The projecting of the -innerxportion of the projectile body 63 through the collar 59 in the form of my invention illustrated adds approximately 20% to the length of travel of the projectile in the barrel without increasing the length of the projectile or bore 51. The projectile length is limited by the internal diameters of .the'relatively small casings required to be perforated. Some-of these casings are only 21/2" inside diameter. Therefore, it is highly important kto secure as long a travel forthe projectile as possible from the time the projectile is released from the restraining collar 59, until it is'cxpelled from the barrel, which travel is required to build up velocity and energy. The muzzle of the barrel ymay be spaced approximately 1/4" from the internal wall ofthe casing being perforated.. The

projectile is required todevelop sufficient velocityV to pierce'two or more walls of such casings and cement between same,` and outside into the formation.

I prefer, 'as shown in Fig. 7, to flare the bottom wall 66a `of the groove 66 in forward direc`v tion, so that such bottom wall 66a will slope out- -wardly in forward direction to meet the front edge 80 of the groove 66. The inner edge face 69a of the gasket ring 61 is outwardly flared in forward direction to correspond to the form of the bottom wall 66a of the groove 66, so that the inner edge face of the ring 61 will engage the Wall 66a. as shown in Fig. 7. The pulPOse of forming these cooperating parts in the manner described is so that when forward :duid pressure is applied to that portion of the ring 6,1, resting in the groove 66, when the collar ,59 is sheared oi, such forward fluid pressure will tend to move the ring of.

metal forward in the groove 66 so that the same will be expanded by the aring wall 66a into y tight engagement with the barrel 56.

jecting radially from its inner end so as to be gripped between said shoulder and said end face of said barrel with the portion thereof which lies forward of Asaid flange extending within said bore, at least one radial face of said iiangeA having a coating of relativelysoft material thereon, a portion of said relatively soft material forming a conoidal enlargement to occupy the flared portion of said bore.

2. In a projectile and barrel assembly for a casingperforator having a body with an opening leadinginward vfrom a face thereof,A said opening comprising a counterbore with an outwardly faced shoulder at the inner end thereof and a pressure chamber inward of said shoulder, the combination of: a barrel securable in said counterbore and having an inner end face confronting said shoulder and having a bore ared at its inner end; and a projectile comprising a body with'a groove near its inner end, a ange seated in said groove and extending outwardly so as `to lie between said s'houlder and said face of said barrel, said body projecting forward into the inner end of 'said bore, there being a coating of relatively soft material on at least the front face of said flange and sealing'the corner formed byl the front face of said ange and the adjacent portion of said body, saidrelatively soft metal also forming a conoidal llet to occupy the flared innerlfend of said bore.

3. In a projectile and barrel assembly for abarrel and beyond Asaid shoulder of said gun body n and into said firing-charge chamber; an annular collar fixed on said projectile at a place a short distance from the inner end of said projectile and extending outwardly therefrom s o that it lies be'- tween said shoulder and said end of said barrel in a position to be gripped between said shoulder and said end of said barrel, said collar supporting'said projectile ina position retracted inwardly of the inner endrof said barrel so as to rest partly in said tiring-charge chamber and partly in said bore, and said collar restraining said projectile from inward or outward movement until the charge in said ming-charge cham'ber has been ignited and suiicient pressure developed to shear said collar; a layer of deformable material operatively associated with said collar to form a seal when said collar is gripped between said shoulder and said end of said barrel; and means for ring the charge in said firing-charge chamber.

4. In a projectile and barrel assembly for a casing perforator having a gun body providing a recess forming a firing-charge chamber and an opening extending outwardly from said firingcharge chamber to the exterior of said gun body, the combination of: an outwardly facing shoulder on said gun body between said ringcharge chamber and said opening; a removable gun barrel secured in said opening, said barrel having a bore extending therethrough and an inner end arranged in facing relation to said shoulder; a projectile having its forward end disposed in the inner end of said bore of said barrel and having its rear end extendingbeyond said shoulder of said gun body and into-said firing-charge chamber; walls forming an annular groove in said projectile spaced a short distance from the rear end thereof; an annularv collar having an inner annular portion thereof resting in said annular groove, means securing said inner annular portion within'said groove, said collar eX- tending radially outwardly from said projectile so that it lies between said shoulder and said end of said barrel in a position to be grippedbe-,fA

tween said shoulder and said inner end of said barrel, s aid collar supporting said projectile in a position retracted inwardly of the inner end of said barrel so as to rest partly in said ringcharge chamber and partly in said bore, and said collar restraining said projectile from inward or outward movement until the charge in said firing-charge chamber has been ignited and suicient pressure developed to shear said collar, and means 'for ring a charge in said firingcharge chamber.

WALDO S. REYNOLDS. 

